Magnesium (Mg)

Why should we concern ourselves with the amount of available magnesium in our soils? What is so important about magnesium? Well, in the context of our world it is every bit as important as oxygen.

Magnesium is the central atom in a molecule of chlorophyll, so no magnesium means no chlorophyll, therefore no plants, no animals and no humans. The amount of magnesium in a soil is the first yield-limiting factor, regardless of how much fertiliser is used. There is no point in spending one penny on any sort of fertiliser until you know whether your soil has enough magnesium. Comprehensive soil testing is vital to prevent waste and avoidable expense. Paradoxically, in areas where Magnesian lime, which is very rich in magnesium, has been used excessively, plant uptake of magnesium falls in inverse proportion to soil magnesium excess. (This paradox also applies to calcium, potash and phosphate.)

In animal and human metabolism magnesium works closely with calcium, but whereas calcium is rarely deficient in the UK, magnesium often is. The most frequently seen symptom of low magnesium in livestock is hypomagnesemia or “staggers”. This deficiency can be induced by the presence of excess potash in spring grass, but is most often seen in lactating dairy cattle which succumb through low blood magnesium levels, where demand for Mg in milk production outstrips dietary supply.

Low magnesium in the human diet can be a causative or contributory factor in a very wide range of diseases and conditions. Tachycardia, arrhythmia, high blood pressure, PMS, menstrual cramps, pre-eclampsia, eclampsia, hyperactivity in children, anxiety, depression, insomnia, chronic constipation are some of them. The trouble is that too much magnesium is almost as dangerous as too little, so the answer is to ensure that the soil has sufficient of this and all other minerals. This way we can leave it to Nature to access them in the right quantities via the plants and animals we eat.

The Field Science system of soil re-mineralisation ensures that magnesium levels are correct within the soil’s rootzone and that the growing plants can acquire the correct balance of nutrients through the soil as nature intended.